High-electron-mobility transistors (HEMTs), also known as heterostructure FETs (HFETs) or modulation-doped FETs (MODFETs), are field-effect transistors incorporating a junction between two materials with different band gaps (i.e. a heterojunction) as the channel instead of a doped region (as is generally the case for MOSFETs). III-N (tri nitride) devices, such as AlGaN/GaN devices, are one type of HEMT that show very promising performance in high-power and high-frequency applications. III-N devices can be used, for example, in high power-high frequency applications such as emitters for cell phone base stations, Direct Broadcast Satellite (DBS) receivers, electronic warfare systems, etc.